Telephone call-box



' (No Model.) 3 Sheets-Sheet 1.

A. GRIFFITH & H. A. BURBANK;

, TELEPHONE OALL BOX.

No. 397,284. Patented Feb. 5, 1889.

Mh'tmeooao gmmhiow I Ff? U (No Model.) 3 SheetsSheet 2.

A. GRIFFITH 8: H. A. BURBANK.

TELEPHONE CALL BOX.

q vii'naooco n. PETERS. muwum mr. Washingkn. 0.0.

(No Mbdei.) 3 Sheets-Sheet a.

A. GRIFFITH 8; H. A. BUR'BANK. TELEPHONE CALL, BOX.

No. 397.284. Patented Feb. 5. 1889.

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AMENJO (lrRlFFl'llI, ()F SPRINGFIELD,

PATENT @rrrcn.

AND HENRY A. liURl-EANK, OF VEST- FIELD, MASSACHUSETTS.

TELEPHONE CALL-BOX.

SPECIFICATION forming part of Letters Patent No. 897,284, dated February5,1889.

Application filed November 6 1888. Serial No. 290,138. (No model.)

T0 whom it may concern:

Be it known that we, AMENZO GRIFFITH and HENRY A. B'URBANK, citizens ofthe United States, residing at Springfield and Vestlield, respectively,both in the county of Hampden and State of Massachusetts, have inventednew and useful Improvements. in Telephone Call-Boxes, of which thefollowing is a specification.

The object of the present invention is to provide means whereby asubscriber using a telephone mayavoid the present special operation ofringing-off, as it is termed, or, in other words, when. through usingthe tele phone temporarily establishing the proper connection with thecentral-oflice annunciator, and by the turning of the magneto-shaftsending a magneto-current through such c011- nection to notify thecentral office that his use of the telephone has been finished; and, inmore direct terms, the purpose of the invention is to provide mechanismwhich may be interposed between the telephone-receiver, supporting-arm,and the driving-shaft of the magneto which will not interfere with allthe usual operations of the telephone as at present carried out, and yeton the downward movement of the receiver-arm, on the han gin of thereceiver thereon, will. cause or permit,

through the downward movement of said receiver-arm, a second operationof the mag neto to signal the central office, the proper 1 electricalcircuit-conneetion, including the magneto and the central-officeannunciator, i at such time being automatically established; and theinvention consists in the construction, combination, and arrangement ofvarious parts, all substantially as will hercinafter fully appear and.be set forth in the claims. 5

The present invention is shown in the accompanying drawings as appliedon the tclephone call-box of the well-known form at i present in generaland universal use throughout the country, and it will be here observedthat the parts constituting said call-box and 1 signaling apparatus arein no material man ner changed,-all connections and circuits being asusual, and in said drawings- Figure 1 is a front elevation of asubscrib- 1 ers call-box with the lower portion of the 1 front or coverbroken away and some parts whereby of the shaft to operate themagneto-electric 100 in section, and showing the automatic ringin g-offdevice as applied in operative relation to the usual mechanism embodiedin said call-box, the said parts being in their posi- 5 5 cuited. liig.2 is an elevation similar to Fig. 60

l. at the lower part of the call-box, but showing the parts in theirpositions at the time the receiver holder-arm is passing from itsuppermost to its lowermost position, at which time the ringing-off will.be automatically ef- 6 5 fected. Fig. 3 is a perspective view, indetail, to be hereinafter referred to, while Figs. 4c and 5 arerespectively a vertical and a horizontal section of portions of themechanism,

taken on the lines 4 4 and 5 5 of Figs. 1 and 2, and which will behereinafter referred to. Fig. 6 is a side elevation of the call-box,illustrating a modified form of the receiver holder or support.

The shaft A, for securing through the crank- 7 5 handle 10 the rotationof the armature of the magneto through means of its gear 12, mesh ingwith a pinion, 13, 011 the spindle 1% of the rotary armature at itspassage through the side wall of the box B, is surrounded by a drum, 0,and -to the shaft within said drum one end of an involute band orclock-spring, 15, is secured, a sufficient number of coils thereof beingdisposed between its secured end and its outer end portion, which isunsecured, but bears with a spring-pressure against the inner walls ofthe drum.

On a turning of the shaft A to generate a magneto-current to signal thecentral office for instance, in the direction of the arrow, 0

Fig. elfrom the centrifugal spring-pressure of the outer end of the coilon the wall of the drum, the said coils will not be immediately turnedin consonance with the shaft, but will be more or less wound up andcapable of an 5 increased recoil; but after a certain extent of rotationof the shaft the spring may drag by its outer end around on the wall ofthe drum, acontinued and indefinite rotation generator may be hadwithout hinderance by or further effect on the spring, but on a re leaseof the force applied to rotate the crank under the recoil of the saidspring the shaft will be rotated in the reverse direction and a secondmagncto-current will be generated.

A sliding shaft, 1), is constrained to move horizontally and withoutrotation through supporting-lugs u I), supported from the U- Inagnets of'the generator or from other suitable part, its one end being providedwith a spring-pawl, d, in position for engagement at the proper timeswith a ratchet-wheel, 10, which is fixed on the shaft A. As will beseen. in Fig. 5, the said pawl loosely encircles the slide-shaitl),andis capable of a partial rotation thereon to an extent regulated by thefixed radial pin 18 on the shaft and the slot 19 in the walls of thepawl, through which said pin enters, and a spiral spring, 20, is applied between the lug u and the pawl to perform the double duty offorcing the shaft outwardly toward the ratchet, and also partiallyrotating the pawl on its shaft, so that its tooth will norn'ially liebelow the roots of the ratchet-teeth. The said spring for theaceomplislnnent of these functions is by one end portion made to embracethe said lug, then to encircle the shaft between the lug and the pawl,and by its other end fastened to the pawl outside of its center ofrotation. The high bent on itself at right angles and extendedhorizontallyin a slotted or bifur cated bracket, 6, outside of the shaftD, between the legs of which is a post, f, fixed on and carried by saidshaft, and which post by its sides bears on the inner walls of thebracket-legs and affords means for preventing the rotation of the saidsliding shaft. The said post is prefita'ably hushed with africtionsleeve,21, and extended outwardly beyond the plane of thebracket 0, receiving, preferably, another and separate f rictionsleevc,22, of reduced diameter.

One particular forn'iation of the duplex sleeved post is shown in Fig.5,1he sleeve parts being held in place by the headed axial pintle 23,passing through said sleeves and the shaft. One or both of the sleevesmight be dispensed with on the post, which, however, would be formed ofthe proper diameter; but for obvious reasons the sleeve provision ispreferred.

Upon the usual swinging receiver holderarm, E, a rigid angular bracket,25, is fixed to move therewith and carries on its inner side a toothedwheel, 26, to engz'ige by its teeth the outer portion of said postf,said wheel being journaled on the bracket for an intermittent rotation,as will appear. Instead of making the teeth of said wheel with theirmedian lines truly radial, the median line of each tooth is a tangent toa circle somewhat outside of the center, such wheel by this formationbeing more effective in its operation, to be hereinafter explained. Aspring-pawl, 27, ishnng on the bracket 95 to engage the said toothedwheel, permitting the rotation of the wheel in one direction andobstructing its reverse rotation, as will be plain on reference to Figs.1, 2, and 5, in the latter ligure the manner of application of thespring 28 for its action on the pawl being shown.

9 71 represent the usual. contact-springs, which, with the contact-screw1 and wire j, form the short circuit :for the magneto, and. which shortcircuit, as well known, is established under the normal relations of theparts of the call-box, and, as shown in Fig. l, at such time renderingthe liue-eircuit inoperativc; but by forcing, through the push-butten7., the spring g away from the contactscrew 1' the line-cirtaiit isestablished for signaling the central office.

A swinging lever, Z, intermediately pivoted on a fixed stud, 30,supported from the magnet or otherwise, has its one arm, 31, lying inproximity to an alnitment-pin, 32, on the slid eshatt I), and its otherarm, 32}, is provided with an aperture, 34-, Fig. 2, through which aconnecting-rod, m, passes, said connectingrod at its end engz'tging thelever-arm be ing screw-threaded, receiving an adjusting and check nut,35, the other end of said connecting-rod passing loosely through anaperture, 3 7, in the outer end of the eontactspring g and receiving ahead at its extremity. Any action of the msh-button and movement of thecontact-spring g, as usual, will have no effeet on the parts of thisinvention, due to the fact that the spring g may loosely slide over therod m; but should there be any undue bind between the spring and rod,whereby the rod would be moved endwise by the spring, said rod by itsother end portion could slide freely through. the aperture in theleverarm 323.

The operation of our improved mechanism is as follows: Jtssuming thatthe parts are in the positions shown in Fig. l, the receiver holder-armbeing held down by the weight of the re ,eiver, then on pressing thebutton to establish the line-connection. with the central oflice andturning the shaft A to generate the signal]ng-eurrent, the spring fromthe rotation of said shaft is put under increased com nfession. The pawl(Z, by its tooth lying against the face of the ratchet at or below thecircular line of the bottom of its teeth, is by the centrifugal forceand action exerted there on by the rotating ratchet thrown outwardly andmoved, with its shaft, by the spring into engagement with the ratchet toprevent the ratchet from being turned in the reverse direction at anundue time. Then on removing the receiver from its lmlder-arm the latterrises under the action of its retractirig-spring 39, earryin g thebracket and toothed wheel 20 therewith; but, as will be observed in Fig.1, a tooth ot' the said wheel being :in contact with the post-sleeve 22on such upward n1ovemen t of the holder-arm and wheel, the wheel will beswung around the extent of: onetooth,

the pawl 27 swinging outwardly against its spring to permit of suchpassage of the tooth The subscriber havi 11g finished by the post.

his conversation and on hanging the receiver on the holder-arm therefor,the holder-arm is again depressed, carrying its toothed wheel 26therewith, and which, being held against rotation backward by its pawland moving by one of its teeth obliquely across the line of thepost-sleeve 22, the said post is forced outward from the said toothedwheel, carrying therewith the slid e-sha ft D, releasing the pawl (1from engagement with the magneto drivingshaft A, and permitting the sameto then rotate under the recoil of its spring 15, which had been putunder compression, as aforesaid, and the movement of the slide-shaft Din a direction away from the ratchet-whecl 16 through the abutment ofits stud 32 against the arm of the lever Z swings such lever on itsfulcrum, and by the engagement of its other end with the connecting-roddraws such rod toward the said ratchet 16 and the contact-spring 9 offfrom the screw 1', establishing the line-connection with thecentral-office annunciator.

In practice, under the rotations of the mag neto-shaft to call up thecentral office more or less, according to the habits of varioussubscribers, the recoil of the spring will always effect a uniformdegree of rotation of themagneto-shaft for ringing off, about onecomplete rotation of said shaft having been effected under a use of theapparatus, and such has been found to afford most practical andsatisfactory results. An advantage worthy of note under the use of theautomatic ring-off mechanism lies in the fact that, by the uniformity ofsuch ring-off signals and of a duration fractional of the ordinarycallin g-up signal, the avoidance of confusion to the attendants in thecentral ofliee will result. Inasmuch as under the increased resistanceapplied on the receiver holder-arm a greater pressure is requiredthereon to depress same to effect the freeing of the magneto-shaft'A andthe establishment of the line-connection, such resistance may beovercome by weighting the receiver or otherwise, one contrivancetherefor being illustrated in Fig. 6, in which a compound-lever systemis employed. The arm corresponding to the one, E, in Figs. 1 and 2, by astud, -10, on its end,'engages a slot 42, in another lever-arm, G, thelatter being pivotally hun by one end on the side of the box B, and hasthe receiver holding-hook formed on its other end, and all as will beapparent without further description.

\Vhat we claim as our invention is 1. In a telephone-call-box, thecombination, with the inagneto-operating shaft provided with theratchet-wheel, the enlarged wall surrounding a portion of said shaft,and the swinging receiver holder-arm, of an involute spring by its innerend secured to said shaft and having its outer end free for aspringbearing 011 said wall, substantially as described, and a pawlnormally located for engagement with said ratchet-wheel, and meansactuated by said holder-arm whereby on the downward movement thereofsaid pawl will be thrown out of engagement with said ratchct, for thepurpose described.

2. In combination, the magneto-shaft adapted to havea spring-reversedrotation and detent devices adapted normally to prevent such reversal,the short-circuit spring and its contact-pin, the swinging receiverholder-arm, and movable connections actuated by the said holder-arm andin engagement with said arm and said short-circuit spring, and also withsaid detent devices, whereby on the downward movement of the saidholder-arm said spring will be drawn from its contacting pin, and saidmagneto-shaft will be freed for its reverse rotation, snbstantially asdescribed.

3. In a telephone-call-box, the combination, with the magnetc-operatingshaft having the ratchet-wheel thereon, the enlarged surrounding wall,and the swinging receiver holderarm, of an involute spring by its innerend secured to said shaft, and having its outer end free for aspring-bearing on said wall, a sliding shaft having a spring-pawlthereon normally located for engagement with said ratchet and providedwith a stud, 22, and a toothed wheel and spring-pawl therefor carried bysaid swinging arm and located in relation to said shaft-stud,substantially as described, whereby on the upward movement of the saidholder-arm said toothed wheel will produce no effect on saidslide-shaft, but on the downward movement thereof said shaft will bemoved longitudinally to carry said pawl out of a position for engagementwith said ratchet, substantially as described.

l. The combination, with the magn eto-sh aft having the ratchet, thesurrounding circularwall and the involute spring, substantially asdescribed, and the holder-arm, of the slideshaft having the stud 22 andpin 18 thereon, and guiding-lugs therefor, the pawl loosely fitted onthe end portion of the slide-shaft, having the slot 19 engaging saidslide-shaft, the spiral spring 20, applied between and se cured to aguide-lug and said pawl for exerting an outward pressure on said pawland slide-shaft, and a pressure on said pawl for a partial rotationthereof on its shaft, and the toothed wheel and spring-pawl thereforcarried by said holder-arm and arranged for operation on and withrelation to said shaftstud 22, substantially as and for the purposedescribed.

5. The combination, with the guiding-lugs (1 and I), the latter havingthe right-angled eX- tension with the longitudinal slot therein, of theslide-shaft I), for carrying the spring-pawl provided with the pin 23,and the sleeves 21 and 22, the form er bearing on the walls of saidslot, substantially as and for the purposes described.

(J. The combination, with the short-circuit contact-spring g and thecontacting part 2' therefor, an d the swinging receiver hold er-arm, ofthe slide-shaft D, having an abutment, 32, mechanism, substantially asdescribed, interter on the downwardmovementof the former, 1 an interniediately-pi voted ti lti n g lever having i one end in engagement withsaid abutment l for being swung thereby, and a eonnecting- 5 rod betweenthe other end of said lever and said eontaet-spring for drawing sa'nieaway from. its contacting part on the swinging of said lever in onedireetion, substantially as described.

7. The combination, with the clmtaet-spring having ana iierture, 37,therein, and the tilting lever I, intermediatetv pivoted and having anaperture, 34-, in one arm thereof, of the conneeting-rod m, by one endportion passing through the spring-aperture 37 and headed thereat, andat its other end portion passing through the lever-arm aperture 3i andscrewthreaded, and the adjusting cheek-nut 35, substantially as and forthe purposes described.

8. In a telephone call-box, the magnetoshaft A, provided with theratchet-wheel and the enlarged circular wall surrounding a por tion ofsaid shaft, the involnte spring by its inner end secured to said shaft,and by its outer end in spring bearing on said wall, the swingingreeeivmholder-arm, and the shorteireuit eonta ot-spring g and itscontacting button 1', combined with a sliding shat't having aspring-pawl normally located for engagement with said ratchet andprovided with a stud, and abutment 32, a toothed Wheel and spring pawltherefor carried by said swinging arm and located in relation to saidshaft for the operation on said slide-shaft, as described, anintern]ediately-pivoted tilting lever, Z, by one arm imposition to'beengaged by said slide-rod abutment 32, and a connecting-rod, m, betweenand in engagement with the other arm of said lever and saidcontactspring g, all substantially as and for the par pose described.

AMENZO GRIFFITH, HENRY A. BURBANK.

Witnesses:

WM. 8. BELLovvs, II. A. CHAPIN.

